1. Field of the Invention
This invention relates to computer system diagnostics, and particularly to service processor circuits.
2. Description of Background
Before our invention computer systems, such as servers, have included a stand-alone microprocessor circuit, also known as a service processor that is used to detect operational faults of sub-systems of the computer system, such as a memory fault, or a hard disk drive fault, for example. The service processor can respond to a detected fault by at least one of writing information into a non-volatile flash memory event log for subsequent interrogation by a service technician, and illuminating light emitting diodes (LEDs) that indicate a sub-system fault that may prevent operation of the computer system as expected.
The service processor is typically powered from an ‘always on’ standby direct current (DC) output from a main power supply, allowing the service processor to detect sub-system faults during a boot-up sequence of the computer system. The service processor will not function to diagnose faults of the main power supply if the ‘always on’ output is, in fact, not on. Accordingly, there is a need in the art for a service processor circuit arrangement that overcomes these drawbacks.